1. Field of the Invention
The present invention relates to a push-to-talk (PTT) phone and, more particularly, to an apparatus and method for controlling a speaker volume of a PTT phone.
2. Description of the Background Art
Upon subscription with a mobile communication service, a mobile communication terminal (referred to hereinafter as a “phone” or “mobile phone”) can make telephone calls to outside parties. This two-way connection is known as an ordinary mobile phone mode for the phone.
Some phones also have a mobile radio function. The phone can function as a walkie-talkie radio with a transmit button being provided on the phone. This one-way connection will be called a push-to-talk (PTT) mode for the phone. In the PTT mode, the user holds the phone away from their face, speaks to the phone from a distance, and hears the other party speaking via a loud speaker, sometimes mounted on the back or sides of the phone. The PTT communication mode is very different from the mobile phone communication mode, where the user holds the phone to their face/ear and speaks directly into a microphone of the phone.
Some PTT type phones have a receiver (e.g. an earpiece in the form of a low volume speaker) which is held against the ear and a loud speaker (e.g. a high volume speaker) which is used during the PTT mode. Some PTT type phones have only one speaker which serves the dual function of the earpiece and the loud speaker. FIG. 1 is a view showing the exterior appearance of a PTT phone having a receiver (e.g. earpiece and a loud speaker), in accordance with the background art.
The PTT phone has two communication modes: an “ordinary mobile phone mode,” which is used when the user wants to use the PTT phone as a typical mobile phone, and a “PTT call mode,” which is used when the user wants to use the PTT phone as a mobile radio. In order to use the PTT phone as a mobile phone, the user can naturally grasp a lower portion of the PTT phone without letting a finger contact with a PTT button and communicate with the other party with the receiver portion of the PTT phone being held against the user's ear and a Mic portion held close to the user's mouth.
In order to use the PTT phone as a mobile radio, the user can press a finger on the PTT button of the PTT phone and communicate with the other party by using the speaker and Mic, with a certain interval maintained between the user's head and the PTT phone, in a facing relationship. It is noted that the way the user holds the PTT phone differs depending on the communication mode the user selects.
However, the background art has drawbacks. If the user forgets that they are using the phone in the PTT mode and holds the phone to their face/ear, as if using the phone in the mobile phone mode, the user will be surprised by the high volume of the voice of the other party from the loud speaker. This problem is partially alleviated when two speakers are provided in the phone and the loud speaker is locate away from the earpiece, such as on the backside of the phone or beside the keypad, as illustrated in FIG. 1. However, even with such a structural disposition of the speakers, the loud speak is still too close to the user's ear to completely avoid the surprise and annoyance of having the loud volume of the PTT mode communication so near to the user's ear.